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Hello guys,
I'm new here and I'm having a hard time figuring out how to use my NanoVNA to measure those things.
I made a search in the group topics but it's always about the results and I can't really find any simple tutorial on how to take those measurements.
- About transformers I would like to measure the ratio but I don't really know where to plug my nanovna to do that and how to configure it.
I have "three outputs" primary, common and secondary. Should I use the 2 ports of the nanoVna to try and obtain a result ?
- for the inductors I would like to know if I can just plug to the 2 ends of it and find it's value ? which value should I show on my display ?
- for the trap filter I used the method where you just go through the inductor with a cable and look at the phase but I'm not really sure it's the best way to do it, can I just plus to A and B on my graph and look at the result instead ?

If you have any link or video that shows the detail of the measurement and wiring process I'd greatly appreciate that.
As I said I'm a new ham so I don't really know how to use my VNA except for measuring SWR of my antenna but I'm convince it's a great tool, I just need to learn how to use it.

Hi Matthew

Good and nice question : it seems to me that harmonics are less reproductible than fondamentals of the LO , so it should have more erratic behavior then calibration will not stay as good as for fondamentals for longer time, indeed when calibration is very new all seems ok even better then annonced -90db dynamic range but after some time it will be -80db after one day may be -70db due to temperature derivation or mecanique position or some battery drop ect , but -60 db is still ok for most of applications including yours , new calibration just before measurement with same conditions will help to have better result i guess , -F version allow different sweep points calibrations for each saver memory c0, c1,c2,c4 .... Still no idea about H4 version .
73's Nizar

Can someone describe the impact of the H4 clock rate on a measurement?

An example: I do an S21 test on a 20db attenuator sweeping 401 points from 1 to 900 MHz (the VNA calibrated across this range). The LOGMAG display shows a completely flat response, 20db across the whole range. The Smith chart shows a tiny amount of inductive reactance that increases (tho still very small) as the frequency goes up.

How does the loss of dynamic range impact my measurement at frequencies above 300 MHz? Is the display, what I see on the screen, less "trustworthy" over 300MHz? Should I interpret the LOGMAG and Smith reports differently below and above 300MHz?
What is the practical outcome of the dynamic range restriction on my test?

For all frequencies above ~300MHz H4 uses harmonics of the clock generator
so it hurts the dynamic range.

On Wed, 6 Nov 2024 at 18:13, Ray Lulling via groups.io <ray=
[email protected]> wrote:

H4 is a wrong device for that range.

Can I ask you to explain further?

the h4 (or other "older" nanovna models) have a clock up to 300 megs and up to 900megs or 1.5ghz is done with third or fifth harmonics
the newer V2, saa2n etc.. are made with a clock up to 4.4ghz or a clock up to 6ghz (litevna62/64)
so they work much better in UHF or higher
dg9bfc sigi

Am 06.11.2024 19:55 schrieb Stan Dye <standye@...>:

On Wed, Nov 6, 2024 at 07:37 AM, Ray Lulling wrote:

I thought the H4 had both chips.

No. All of the vna models I am aware of have only one. The MS vs SI chip is really an 'available supply' issue rather than a performance one. The firmware selection is to accommodate whichever one is in your device.
And as the previous poster said, if you primarily want to work at 850MHz-1GHz, you would probably be happier if you pay a bit more and choose the litevna64 or one of the V2 models that are designed for higher frequencies.
Yes, the H4 will 'work' up beyond 1.5GHz - but its performance drops off significantly as you go up in frequency. Its best performance is up to 300MHz, and it still works reasonably well up to 800 or 900MHz (its original spec'd top frequency) - but regardless of which chip it has, all of these higher frequencies have a much decreased dynamic range.
The units units designed and advertised for 4-6GHz have many of the same issues at their highest frequencies, but work much better than the H4 at 800-900MHz and in the low GHz range.

H4 is a wrong device for that range.

Can I ask you to explain further?

Seeing you mention “thermal camera” does anyone else have recommendations
for such a device. I see low cost gun type at the big box stores and have
heard of more expensive units that show a picture (like for looking for heat
loss in a home). Any suggestions and URLs? Thank you.

Be the REASON someone smiles today.

Dave K8WPE

This is a list I generated when i was trying to sell my employer on getting one or more.

There are some super cheap bare knuckles units. But they have supper low refresh, low resolution, poor detection or really bad software.

It is important to note that even the mobile devices made by Flir have low resolution and poor detection. Which is odd barbecue it's Flir... However what they do offer are devices with stand alone batteries which means they don't overload your phone while running and they seem to have pretty good software. The better units, both 3rd party and Flir will attempt to combine multiple images to create an over lay which enhances the image.

My opinion is to seek the best bang for buck in the highest resolution, able to detect the range you need to work with and decent software.

While less valuable, it worth note that certain over seas phone developers have been including either IR or Thermal in their phones. One finally has a really good higher resolution thermal camera. The phone also has like 5 more cameras built in. They cost about the same as buying one of these higher end models on amazon and come with a massive battery. So even if you only use the device for the camera, it might be worth the thought. Reviews are mixed, and don't expect updates...

H4 is a wrong device for that range.

On Wed, 6 Nov 2024 at 16:37, Ray Lulling via groups.io
<ray@...> wrote:

I thought the H4 had both chips. One was better at higher frequencies and the other better at lower. So the firmware offered a way to switch which chip was being used to get better results?
Our needs for instance are mostly in the 850 - 1000 Mhz range.

I thought the H4 had both chips. One was better at higher frequencies and the other better at lower. So the firmware offered a way to switch which chip was being used to get better results?
Our needs for instance are mostly in the 850 - 1000 Mhz range.

On Wed, Nov 6, 2024 at 01:48 AM, Team-SIM SIM-Mode wrote:

did you mean that plastic cases used on H4 has inside an aluminium painted
layer for good sheilding ??

They have internal metal shields on the PCB assemblies.
73, Don N2VGU

The SAA-2N, which I have and recommend, is in a steel case with 4 inch display and with type N connectors, and the test cables and calibration standards are also type N. The cables and standards are robust and appear well-made. It comes in a nice carry case.
I have two of the other nanoVNAs and the SAA-2N is the one I reach for the most.

73, Don N2VGU

Hi Stand
Thanks for info, did you mean that plastic cases used on H4 has inside an aluminium painted layer for good sheilding ?? So no mater if case is metalic or plastic ..
73s Nizar

The H4 has a plastic case, unless someone repackaged it. Metal case units have a different name, different support (don't remember what it is).
Don't shy away from the plastic - it works very well, and does not seem to suffer from a lack of shielding.

Hi all

Whats is the tic to know if NanoVna-H4 to buy has a plastic or a metalic case ?

Thanks
73's Nizar

Yes, those are the different makes of the clock generator chip.
If you have an older -H, you have the SI.
If you have the MS, your hardware version number on the back will have an "MS" in it.
I'm not sure of the exact marking for the SM_ST, but it will also be in the hardware version number on the back, and you don't have it unless you got a new nanovna this year.

And... the MS and SI builds are identical except for the initialization of the clock gen type variable, which you can set under the expert settings menu, so either file will be ok as long as you go into the menu and make sure the correct type is set.
Stan

Why on there are there multiple options to download for NanoVNA-H?
What is the difference between:
NanoVNA-H-MS_20240220.dfu
NanoVNA-H-SI_20240220.dfu
NanoVNA-H-SM_ST_20240220.dfu ?

The MS, SI, postfix, are those the type of the clock generator in the NanoVNA?
How do I tell which one is for my device? (NanoVNA-H)

Thanks much for that info on the time and date. I had a friend add the crystal and the micro SD socket months ago and I never knew if they worked or not. So I know that one mod works now.

One thing you might try - most cell phone cameras will see down into the near infrared (I can see the flashes from my TV remote on my camera). You could try that. I would recommend doing it in a dark room so that the ambient light doesn't wash out any thermal signatures.
It might or might not work, but it's free. :)

73.
Jerry, AI0K

I am also almost certain of a bad battery. I would definitely test it with a 6V (bicycle) lamp or something similar.
You can also temporarily connect ANY 3.7V Li-ion battery (from GSM, DECT telephone, computer ...) and see what it does.
But I also once had to replace the voltage regulator 5303 because the battery did not charge.
Placing a new 5303 (of 5 pieces) was also not good for an unclear reason (I think it was a bad series).
I then bought a 5606 (10 pieces from Ali) and it turned out to work perfectly in the circuit.